The classic symptoms of acute sinusitis usually follow a cold that does not improve, or one that worsens after 5 to 7 days of symptoms. They include:

• Nasal congestion and discharge
• Sore throat and postnasal drip (fluid dripping down the back of your throat, especially at night or when lying down)
• Headache -- pressure-like pain, pain behind the eyes, toothache, or facial tenderness
• Cough, often worse at night
• Fever (may be present)
• Bad breath or loss of smell
• Fatigue and generally not feeling well

Symptoms of chronic sinusitis are the same as acute sinusitis, but tend to be milder and last longer than 8 weeks.

Your doctor will test for sinusitis by:

• Tapping over a sinus area. Tenderness may indicate infection.
• Shining a light against the sinus (called transillumination). If dark, this indicates possible inflammation.

Other tests that might be considered include:

• Viewing the sinuses through a fiberoptic scope
• Ultrasound
• X-ray of the sinuses
• Cultures of the material from the nose

However, these tests are relatively insensitive for detecting sinusitis, and are often considered unnecessary.

A CT scan of the sinuses is a much better test to help diagnose sinusitis. If sinusitis is thought to involve tumor or fungal infections, an MRI of the sinuses may be necessary.

If you have chronic or recurrent sinusitis, further laboratory evaluation may be necessary to look for an underlying disorder. This may involve sweat chloride tests for cystic fibrosis, ciliary function tests, blood tests for HIV or other tests for immunodeficiency, allergy testing, or nasal cytology (checking the cells in the nasal secretions).